The new 1984 IT490 build thread...

[Vonski]

she's a beauty

Thanks man, I'm really liking how its turning out.

BTW, on the shock spring... apparently, many of the Suzuki RM250s ran the SRSP 6727 and most are yellow.

 

[anderson750]

You know that Brad Strong overalled a bunch of races on this bike back in the day?

 

[Vonski]

You know that Brad Strong overalled a bunch of races on this bike back in the day?

That's pretty badass. I know Brad, but not well... just marked course in Page with him years ago.

 

[Rot Box]

Looks awesome! I like how it's been in the family since new pretty cool if you ask me.

If you haven't already I'd recommend using loc-tite, nyloc nuts or safety wire (where applicable) on everything. Something about the big bore 2T's when it comes to plastics, suspension, exhaust hangers--it doesn't matter what it is if it has threads it will vibrate loose at some point

 

[Vonski]

If you haven't already I'd recommend using loc-tite, nyloc nuts or safety wire (where applicable) on everything. Something about the big bore 2T's when it comes to plastics, suspension, exhaust hangers--it doesn't matter what it is if it has threads it will vibrate loose at some point

Yep, we've been using plenty of blue Loctite on this thing. With the kickstand down and idling, it vibrates itself across the driveway until it runs out of cement.

 

[Rot Box]

With the kickstand down and idling, it vibrates itself across the driveway until it runs out of cement.

Haha yep

 

[Vonski]

Got more parts in the way of a Motion Pro clutch cable and a Factory Connection shock spring (yellow, of course). Still hoping to find a used Nissin front brake perch/master cyl./hose setup if anyone has one for sale. Hoping to find something local.

 

[Vonski]

On these older shock bodies, the OD is not threaded. Instead, they have a couple snap-ring grooves to accomplish the same thing, but with much less adjustability. Now that I have the new spring and correct rate, I can't achieve the right race sag/ride height without machining additional snap-ring grooves in the body. Looks like some lathe work is in order.

 

[rholbrook]

Obviously back then that wasn't important

 

[Vonski]

Obviously back then that wasn't important

Obviously back then that wasn't important

Ha! Remember when we'd just ride everything as-is and not think twice about it? I kinda miss that. Getting my modern bike's suspension to work "right" (whatever the hell that is...), consistently keeps me up at night.

 

[Vonski]

FWIW, here's the bare shock body with the 3 stock snap-ring grooves. Kinda scrawny by todays standards, but will get the job done. Too bad it was recently rebuilt (wasted oil and nitrogen).

 

[rholbrook]

I was looking at the 490 and couldnt help but notice the size of the rear hub. It would be interesting to see what the weight difference was between the 490's rear wheel and your 300's rear wheel.
Have you put the whole bike on the scale yet?

 

[Vonski]

I was looking at the 490 and couldnt help but notice the size of the rear hub. It would be interesting to see what the weight difference was between the 490's rear wheel and your 300's rear wheel.
Have you put the whole bike on the scale yet?

Sorry man, I've been dropping the ball on weighing stuff. I will definitely get the bike on a scale once fully assembled. Next time I've got the rear wheel off, I'll weigh that too (as I'm curious now how it compares to a modern wheelset).

 

[Vonski]

A big thanks to Carl for the use of his lathe. :greg: 1 groove would've been good enough, but I cut a couple more for good measure.

 

[Vonski]

Threw the new clutch cable on yesterday and the clutch pull certainly won't require 4 fingers now, but I'm kicking myself for not getting a new return spring. I should have known a 30 year old return spring probably wouldn't be very functional.

 

[Vonski]

and back on track...

Rear shock reassembled, oil added, and charged with nitrogen. As mentioned before, (for early '80s technology) I'm pretty impressed with the shock. The remote reservoir doesn't have a modern schrader valve and the comp. and rebound can only be adjusted in equal amounts, but the fact that it has a remote res. and has the range of adjustment it does is impressive. Of course, it will get swapped out in favor of a modern shock if it gives us any trouble.

 

[Vonski]

Threw the shock back on yesterday. Since the linkage and angle of the shock is quite a bit different than a modern bike, sag cannot be dialed-in using common numbers, so we'll just have to wing it for now and adjust as needed. I settled on a 5.4 rate spring, and although its a HUGE improvement over the ridiculously soft stock 4.0, I still might have to go a bit heavier.

 

[rholbrook]

I saw an IT175 in the back of a truck in Bountiful this afternoon. I was at the top of 4th North where it comes down from the "B". My friends dad bought one of them new when we were kids and it was so much fun to ride. It was such a huge difference from my YZ80

 

[Rot Box]

Good work on the shock

although its a HUGE improvement over the ridiculously soft stock 4.0

Something about the 80's... My 84 CR came stock with a 4.5 and it would bottom on everything

 

[Vonski]

It was such a huge difference from my YZ80

Those were great bikes! Here a pic of my '82, first year of the water cooled 80. That's right, white Levi's and a trucker hat. :greg: